Electrical apparatus



July 10, 1934.

L. A. M. PHELAN AL ELECTRICAL APPARATUS 23. 1922 2 Sheets-Sheet 1Original Filed Dec he/an trill Cit/Edge y 1934- Y LA. M. PHELAN ET AL19,235

ELECTRICAL APPARATUS Original Filed Dec; 2:. 1922 2 Sheets-Shae? 2'IIIIIII A Reissues] July Our invention relates to electrical switchesde-, signed particularly for the regulation or control of electricalcircuits, such as may be used in connection with heating, cooling or andsystems.

The subject matter 0 ELECTRICAL mmros Louis A. M. Phelan, Chicago, IlL,and Cliilord Hotchkiss, Elkhart, Ind., assignors, by mesne assignments,to Minneapolis-Honeywell legulator Company, Minneapolis, Minn, acorporation of Delaware Original No.'1,676,921, dated July 1c, 1928,Serial No. 608,703, December 23, 1922. Application l reissue July 9,

1930, Serial No. 486,896

as Clainu. (o1. soc-139) tainer is prop rly actuated.

edtomechauicalabuseandwhenimedinconnection with considerable quantities0! electric.

tactor oi the above mentioned type, mounted in coniimction with anexpansible and contractible element, such as heat or pressure responsivedealarm apparatusthis invention has reference to a device making use ofa liquid electrical .contactor tube, which comprises a container inwhich'are mounted spaced electrodes adapted to be bridged'by a body ofmercury when the con- Flg. 5' shows a modification having still anothertype'of casing or housing;

Fig. 6 is a detail sectional view similar to Fig. 3, taken along theline6-6 of Fig. 'l, but showing a modified form of thermostatic element andcontactor tube;.

Fig. is'a front view of and,

Figs. 8 and 9 are detail sectional views of huther modifications.

the device of Fig. 6;

In a general way our invention, as shown in Our invention makes use ofan electrical con- Fig. 1, comprises the liquid contactor tube I mountedupon a conical spiral thermostatic bimetallic element 2, which in turnis pivotally mounted at 3 to the frame or support 4. A cover vices, .oras curved pressure tubes and thermo- '5 serves -to protect and enclosethe device.

static elements. The pressure responsive or thermostatic element isdesigned to support and serve to actuate the electrical contactor. intoor More particularly our device refers toanelectricswitchotthistypeinwhichthepressureor thermostatic element isunusually emcient, ac-

curate and rapid in operation.

. A'iurther particular object of our invention istopmvideareadymeansioradiustingtheabove operate atpredetertypefotde'viceto Another -readiiy energy will object oi ourinvention -tubeottheabov echaracter, which upon an actuating dea verysmall quantiiw contactor tube and require only a small change inprestemperature for its actuation. I

object of our invention is to provideswitchdeviceoithetypeindicatemthatwillbe and economical to construct andwhich will possess great durability, even when subjectmoimted availablefor actuating the current at substantial voltages.

Also further objects and advantages wlllappear from the followingspecification and accompanying drawings, in which- I Figure 1 is anelevation view partly in oi my invention;

Fig.2isasectionalviewtakenonline22oi Pia-1:

I'lg.3isadetailsec modification having a is to produce a tionalviewtaken The tube 1 is constructed in 'a substantially toroidal form,preferably in the form of a torus.

the tube is evacuated and filled with aninert gas and sealed oil throughthe tip 6. Electrodes the tube and may be formed oi. platinum or o!Dumet wire covered or plated with casings of pure iron or the like metalwhich is unafiected' by the arcing obtaining in the tube in the presenceof the mercury and the mercury vapor. A body of conducting fluid 9,preferably mercury, may substantially.fill the lower half of thecontainer 1- and is normally in contact with the electrode 8. When thetube is tilted in the proper direction,

relation with the electrodes-7 and. 8, thusclosing an electrical circuitthrough the tube.

' Since the tube is oi toroidal term and is mounted to be tiltedsubstantially about its geometrical axis, it will be noted that the bodyof mercury 9 will remain practically stationary and .of constant-shapewhenthe tube is tilted into or out of circuit making podtion. Inotherwomathebodyoioonductingfiuidaaswell as the tube 1, retains substantiallystatimiar'y center oi gravity-when the tube is actuated. Hence it isobvious that very little. energy is requiredeithertoinitiallymovethetubeorto returnthetube toitsnormalpositiomsincethe parts remain practicallybalanced at all times. In the former types of-liqui'd contactor tubes,it hasbemnecemarytodisplaceafairlylargemam Such contactors have thefurther disadvantage that an appreciable temperature obs-n8 isrequiredto restorethepartsincluding the'bodyoi conducting liquid totheir normal position after .onee

on line the bodyci mercury 9 will come intobridgingofheavyliquidinordertoactuatethedeviee.

After the various parts in the tube are in place,

'7 and 8 are inserted and sealed in the walls of for mounting the of abi-metallic ribbon composedof layers of any suitable metals or alloys,such as brass and nickel, and is wound substantially in the shape of aconical or helical spiral as shown. This form of winding has aparticular advantage over. the more usual simple spiral form in that amuch larger portion of the surface area of the thermostatic ribbon orheat responsive element is directiy exposed to the atmosphere and aircur,-

rents. This is an important consideration when this type of device isused for accurate and rapid temperature regulation. This form; ofconical spiral mounting has a further advantage in the presentstructure, in that it .makes possible a more convenient arrangement ofthelead wiresto the contactor tube and permits the contactor.

tube to be flexibly mounted at a central position in the casing remotefrom, any of the fixed parts of the structure which would possibly hitagainst and break the glass tube.

The inner end of the 'spiral element 2 is mounted upon a pivoting shaft3 which is retained in a frame 4 by a nut 3a and washer 3b. A collar 11surrounds the pivoting screw 3 and is fixed to the spiral element 2 bysolder or by means of a screw 12.

The collar 11 is provided with an extension 13 which forms a handle foradjusting the angular positionof the tube land the spiral element 2about its pivoting shaft 3. The handle 13 extends to the exterior of thecasing and is provided with a pointer 14 co-operating with a calibratedscale 15 formed on an extension of the frame 4.

The electrodes '1 and.8 are connected in the circuit, respectively, bythe flexible lead wires 16 and 17. The flexible wire. 16 is attached tothe outer end of the spiral element 2 so that the electric currentflowing in the circuit will trav-- erse this element for the particularpurpose hereinafter described. From. the spiral element 2' the circuitcontinues through frame 4 to a bind-' ing post 19. The flexible lead 17is connected to a binding, post 20. The binding posts 19 and 20 serve toconnect the device to the desired externalcircuit.

The cover 5 is attached to the frame 4 by means of lugs 21 formedintegral with the lower end of the frame 4 and by a lug 22 formed at theupper end of the frame 4 and engaged by a screw 23. Openings 24 areprovided in the cover 5 for the 1 purpose of permitting free circulationof aircurrents about the thermostatic element 2. The

cover 5 is provided witha thermometer 25 which serves as a guide whenadjusting the switch to actuate at a desired temperature.

Screw holes 26 may be provided in the frame 4 device upon a wall orpartition In Fig. 4, the device is shown mounted in a modifled form ofThe casing here consists of a-body portion 2'! and a cap portion 28having a flange 29, which is intended to be mounted flush with a wallsurface. In Fig. 5, the device is shown mounted in another modified formof easing, comprising a rear enclosing frame 30, a mounting plate 31,and

.a cover portion 32. The rear frame 30 constitutes a weather-proofconnection box for the .'electrical leads and is provided with athreaded opening for a conduit connection.

In Figs. 6 and 7, a modified structure is shown in which a cylindricalcontactor tube 36 is used. The tube 36 is designed to be normallylocated in a position neighboring the horizontal and upon being tilted,a body of mercury 37 is designed to flow into and out of bridgingrelation with a pair of electrodes 38 and 39 which are connected incircuit in the manner of electrodes 7 and 8 above described. A contactortube of this type has been found to be accurately responsive to veryslight changes in its angular position and consequently is desirable foruse'where only small changes in temperature occur. The

tube 36 is mounted upon a spiral element 40 by means of a. spring clip41. It will be noted that the spiral element 40 is shown in an invertedposition from that shown in Fig. l, in order to accommodate more readilythe cylindrical type of contactor tube; The spiral element 40 isattached by means of rivets 42 to a supporting arm 43. a

In Fig. '8, a further modification is shown in which a hollow spiralthermostatic element 44 is'used. The hollow portion of this spiralelement may form a continuous passage throughout the length of thespiral and may be connected at an end, if desired, with a container 45.The passage through the spiral element and the container 45 may befllled with air or other fluids,

which when heated will result in a'- change in pressure. This pressurechange will serve to alter the shape of the spiral element 44 and thusactuate the contactor tube. It will be understood that container 45 ismerely disclosed as an e xample of a source of pressure changes and thatthe contactor tube and spiral element shown in Fig. 8 are capable of usewith, and may be actuated by, other desired sources of varying pressure.

In Fig. 9, a modification is shown embodying features shown in Figs. 3and 8. A hollow spiral element 46 is shownhaving outer and inner walls46a and 46b composed respectively of materials having difl'erentcoeihcients of expansion. This spiral elementmay also be attached to asource 7 of variable pressure, such as the fluid container 47 and hencethis element issubject to an alteration in shape when temperaturechanges occur, both because of its bi-metallic nature and because of itsaction as a curved pressure tube.

mail of the above described structures it will be noted that the use ofhearings in the operating parts of the mountings ofthe contactor tubesis entirely eliminated. Consequently the spiral elements when actuating'the contactor tubes,

are not required to overcome any variable frictional lomesas wouldresult with the use of bearings.

The operation and one method of using the device of Fig. 1 will nowbe-outlined. The binding posts 19 and-20 are connected directly inseries with the circuit which is to be controlled such, for example, asthe circuit of a motor controlled heating q efit of any of the usual andsuitable UP that the room temperature is at or near the desired point,the lever 13 is turned so that the contactor tube-1 isin a substantiallyneutral pofltion ready to either close or open the circuit with a veryslight change .of temperature.

If it is assumed the device is being used for heating apparatus shouldnot be in full operation and consequently the contactor tube-should bein open circuit position with the body of mercury 9 out of contact withthe electrode '7.

However, as the room temperature drops a predetermined amount. thethermostatic element 2.

will become modified in shape because of the ternperature change andwill rotate the contactor tube 1 about its axis into circuit closingposition. The current to the contactor tube will now flow through thespiral element 2 and. will start the operation of the heating equipment.The spiral element 2 will thereupon begin to return to its normalposition and will begin to rotate the contactor tube back to itsformerposition as a result of two causes: first, the heatingequipment willhave partially restored the room temperature and second, the currentrunning through the spiral element will furnish a slight amount of heat,thus aiding in quickly bringing the temperature of the spiral element 2back to normal.

This current heating efl'ect obtaining in the element 2 has a particularadvantage in this type of heat regulating switch which will now beoutlined. When the contactor tube 1 turns to its closed circuit positionit will tend to remain there for a slightly longer period thannecessarydue to'inertia of the heating apparatus and to the timeirequired tobring the room temperature and the temperature of the thermostaticelement back to normal. This will result in a room tempei'ature inexcess of that desired before the thermostatic element is sufilcientlyheated to cause the heatingequipment to be shut oii. Hence, in order touse this type of regulating switch where the temperature must beregulated very accurately, it is advisable to supplement the action ofthe increased room temperature upon the spiral element 2 with theheating action of the current flowing through this element. With such adevice it has been found possible to regu-- late the room temperaturewith an accuracy several degrees closer than with the former methodsHowever, in case this type of thermostatic switch is used in connectionwith the control of refrigeration orcooling apparatus, it willordinarily be connected in circuit and adjusted to open the circuit uponthe occurrence of a sub ficient drop in temperature- This is theopposite of its action when used with heating apparatus .where it servesto open the circuit upon the occurrence of 'a sufiicient increase intemperature. In, view of these facts, the heating effect of the currentthrough the spiral element is not required' in the case of refrigerationand cooling apparatus. Consequently in the device as shown in Fig. 4,the current is not connected through the spiral element but independentlead wires 16a and 170 are. provided to the binding posts. In otherinstances it may be desirable'to pass only a'portion of the totalcurrent through the spiral element and in such cases a shunt wire 16b,as shown in Fig. '5, maybe so designed to by-pass the desired amount ofcurrent;

The terms contactor', "li uid contactor. and electrical contactor asemployed in the claims contained herein refer to the well known type ofmercury electric switch or an equivalent there-.- of which comprises anhermetically sealed con-- tainer having electrodes disposed therein anda body of conducting liquid, such as mercury,.which serves to make andbreak the electric circuit between the said electrodes. The variousmodithe regulation of heating equipments and that the room is at thedesired temperature, then the fications of our invention shown in thedrawings are illustrative of several types of such contactors as arecovered by our present invention. It is obvious, therefore, thatthe'above-mentioned terms do not pertain to an open and exposed contactmember which is movable by the coiled thermostatic element and which isadapted to control an" electric circuit by cooperating with a second andfixed open contact member.

While we have shown and described several embodiments of our invention,it is to be understood that manymodificationsmay be made therein withoutdeparting from the spirit and scope of the appended claims, and wedesire that only such limitations shall be imposed upon our inventlonasare specifically pointed out in the claims and such as are required bythe prior art.

Having thus described ourinvention, what we 7 claim as new and desire tosecure by Letters Patent in the United States, is:

"1. An electric switch comprising a coiled expansible and contractibleelement, a liquid contactcr wholly supported on and movable with saidelement, 'a body of conducting liquid housed in said contactor, and anadjustable supporting means for said elementfor adjusting the positionof said contactor.

.2. A thermostaticswitch comprising a heat responsive element formed ofconducting material,

and a liquid contactor comprising a container, oo-

operating electrodes sealed therein and a conducting body housed in saidcontainer, said contactor being wholly supported upon one end of saidelement and one of said electrodes being electrically connected incircuit relationship to said element.

3. A thermostatic switch comprising a heat responsive element formed ofconducting material, and a liquid contactor comprising a container,cooperating electrodes .sealed therein and a conducting body housed insaid container, said con-' tactor being wholly supported upon a free endof said element, and said element being electrically'connected to one ofsaid electrodes whereby the current that may .fiow in said circuitserves to heat and thereby tends to actuate said element'.

' '4. An electric switch comprising an expansible andcontractibleelement, and an electrical ll uid contactor, including co-operatingelectrodes of opposite polarity, said element being fixed at one s endand free at its other end and said electrical trical liquidcontactor,including cooperating electrodes of opposite polarity, said elementbeing fixed at one end and free at its other end and said electricalliquid contactor bei g wholly supported upon said free end, and meansfor adjusting the angular position of said element and said cohtactor.

6. An electrical switch comprising acoiled tube filled with a volatilefluid, and a rotatable electrical contactor, said tube being fixed atone end and its other end being free to impart movement as said tubeexpands and contracts, and said contactor being mounted immediatelyadjacent to said other end and connected directly thereto so as torotate about the axis of said tube.

- 7. An electric switch comprising a coiled expansible and contractibleelement, a liquid contactor mounted at the inner end thereof andtiltable about the axis of said coiled element, and

element, said supporting means being in turn pivotally mounted in orderto provide for adjustment of the angular position of "the said liquidcontactor.

' 8. An electric switch comprising a coiled expansible and contractibleelement, a liquid contactor mounted on the inner end thereof, andadjustable supporting means having in turn a mounting pivotedsubstantially coaxially with said coiled element in order to provideforadjustment of the angular position of said liquid contactor,

9. A thermostatic switch comprising a heat responsive element, a liquidcontactor operable.

upon being tilted and wholly supported on the free end thereof, andsupporting means fixed to the other end of said element, said supportingmeans being pivotally mounted in order to provide for adjustment of theactuating position 01' said liquid contactor.

10. An electric switch comprising an expansible and contractibleelement, amounting towhich one end only of said element is fixed,atiltable contactor mounted and wholly supported upon the other end ofsaid element, said contactor comprising a container, electrodesthereinand a conducting body movable therebetween, and means for adjusting thetilting angle of said contactor.

11. An electric switch comprising an expansible and contractible elementin the form of a substantially conical spiral, the end of said elementat the base of the conical spiral being fixed, and an'electricalcontactor wholly and tiltably supported upon the end 01 said element atthe apex of the conical spiral 12. A thermostatic electric switchcomprising a coiled thermostatic element having only one of its endsfixed, a liquid contactor operable on'being tilted and supported whollyupon the other end of said thermostatic element, and means for vadjusting the angular position of said liquid, contactor therebypermitting said thermostatic element to tilt said contactor atpredetermined temperatures.

13. A thermostatic switch comprising a coiled thermostatic elementhaving only one of its ends fixed, a liquid contactor operable on beingtilted wholly carried by and mounted upon the free end of saidthermostaticelement, and means for adjusting the angular position ofsaid liquid contactor to permit said thermostatic element to operate itat difierent predetermined temperatures.

14. An electrical device comprising a coiled expansible and contractibleelement, a mounting ,member, 'a bracket mounted on said mounting memberand having one end only of said element secured thereto, a liquidcontactor operable on being tilted and mounted at the other end of saidelement, said bracket being adjustable for vary ing the angular positionof said liquid contactor thereby permitting said element to operate saidliquid contactor under predetermined conditions.

15. An electrical device comprising a spirally coiled expansible andcontractible element, a mounting member, a bracket adjustably pivotedupon said mounting member, the outer end of said element being securedto said bracket, and a liquid contactor mounted at the inner end of saidelement at its 'axis and connected to said inner end whereby movement'isimparted thereby to actuatesaid liquid contactor.- g

'16. An electrical device comprising a coiled expansible andcontractible element, a mounting member, a bracket pivoted upon saidmounting member, one end of said coiled element being semounted at theother end'oi. said element and connected thereto whereby movement ofsaid other end may be imparted to; said liquid contactor for tilting thelatter.

17. ,An electrical device comprisinga coiled actuatin'g element, amounting member a bracket adjustably secured to said mounting member,one end of said element being secured to saidbracket, and a liquidcontactor wholly supported uponan carried by the free end of saidelement. 7 18. A thermostatic switch comprising a thermostatic coil, amounting member, a bracket pivotally secured to said mounting member,the outer end of said coil being attached to said bracket, and a liquidcontactor wholly supported upon the free end of said coil. 19. Anelectrical device comprising a' thermostatic spirally coiled element, amounting memher, a bracket pivoted thereto, the outerend of said elementbeing attached to said'braeket, and.

a liquid contactor disposed at the axis thereof, said contactor beingwholly supported upon the free end of said element.

20. A thermostatic switchcomprising-a coiled -actuating element, aliquid contactor operable upon being tilted and mounted upon the freeend of said coiled element adjacent to the axis then.- of, andsupporting means to which the other end of said coiled element isattached, said supporting means being adjustable to provide for adjustment of the tilting {angle of said contactor.

21, An electrical device comprising a thermostatic coil, a liquidcontactor operable upon being tilted and mounted adjacent to the axisthereof and wholly supported upon the free end ofsaid coil, supportingmeans to'which the other end of said coil is secured, said supportingmeans being adjustable in order to provide for varying the actuatingposition of said contactor, and electrical connections for saidcontactor said coil as a part thereof. 4 .22. An electricswitchcomprislng an actuating element having only one end thereof fixed,a tiltable liquid contactor being mounted and wholly supported upon thefree endof said element, said contactor comprising a container,

electrodes therein and a conducting body movable therebetween. and meansfor adjusting said actuating element whereby the tilting angle of saidcontactor for opening, and closing its associated electric circuit maybe varied.

' 23. An electricswitch comprising a heat responsive actuating elementhaving only one end thereof fixed, a tiltable contactor mounted andwholly supported upon the tree end-of said ele end of said element isfixed, a tiltable contactor constituting secured to and wholly supportedupon the free end of saidelement, said contactor comprising a container,electrodes therein, and a conducting body mova 1e therebetween, andmeans'for adlusting sai thermostatic element" whereby the tilting angleof said contactor may be varied.

25. An electrical switch comprising a coiled expansible and contractibleelement, and a rotatable electrical contactor, said element being fixedat one end and being free at its other end toimpart movement as saidelement expands and contracts and said contactorbeing mountedimmediately adjacent tosaid other end and connected directly thereto soas to tilt about the axis of said element by the movement impartedbyLsaid other end. v a

26. An electrical switch comprising a coiled expansible and contractibleelement, an electrical contactor, said element being fixed at" one endand being free at its other end to impart movement as said elementexpands and contracts and said contactor being mounted-adjacent to andtiitable about the axis of said element and being tiltable by themovement imparted by said other end, and adjustable means for varyingthe position of the fixed end of said element for varying the tiltingangle of said contactor.

27. An electrical switch comprising a spirally coiled expansible andcontractibie element, an electrical contactor mounted adjacent to andtiltable about the axis of said element, said element being fixed at itsouter end and being free at its inner end to impart tilting movement tosaid contactor as said element expands andcontracts, and means foradjusting the position of the fixed outer end of the said elementthereby varying the tilting angle of said contactor.

28. An electric temperature control switch comprising a heat sensitiveelement responsive primarily to the ambient temperature to becontrolled, an electrical contactor, a holder therefor adapted to bemoved in response to temperature changes to which said heat sensitiveelement is subjected, and means for additionally thermallyinfluencingsaid heat sensitive element through the medium of theelectric current flowing through said electrical contactor.

29. An electrical temperature control switch comprising a heat sensitiveelenient responsive primarily to the ambient temperature to becontrolled, a member associated therewith and moved thereby inresponse'to temperature changes to which said heat sensitive element issubjected. and an electrical contactor carried by said member, said heatsensitive element being thermally influenced additionally by the currentflowing through said electrical contactor and said additional thermalinfluence being discontinued when said electrical contactor moves toopen circuit position.. v

30. A control mechanism for maintaining the temperature of an ambientmedium substantially uniform comprisingin combination with electricswitching means, of a temperature respon-' sive device responsiveprimarily to the temperature of the ambient medium which temperature isto be con lied to substantial uniformity, and means opera velyconnecting said device and said switching to one positiomg said devicewhen the latter responds to a c e in one direction of the temperature ofthe ambient medium for maintaining said-temperature within the normalrange to establish substantial uniformity thereof, such operation of theswitching means also controlling the transmission of auxiliary heat to'said device whereby said devicewill respond to the combined effect ofthe temperature of'the ambient medium and the auxiliary heat to operatethe switchingmeans to its other position at a different point in therange of the ambient temperature than would.

be the case if the device was responsive only to the temperature of theambient medium to the exclusion of the auxiliary heat. I

31.'A control for maintaining the the latter 'being operated temperatureof an-ambient medium substantially uniform comprising in combinationelectric switching means, and a thermal actuatorprimarily responsive tothe temperature of the ambient medium operatively connected to saidswitching means and'adapted to move the same to circuit opening andclosing positions in response to changes in the temperature of the am-.

bient medium under control, actuation of said switching means to one ofits positions being effected solely by the temperature of the ambientmedium and when moved to said position then controlling the transmissionof auxiliary heatto said actuator whereby the switching means will beoperated to its other position in response to the combined action uponsaid actuator of the auxiliary. heat and the temperature of the ambient=m'edium under control.

32. A control mechanism for maintaining the temperature of an ambientmedium substantially uniform comprising in combination electricswitching means, and a thermal actuator responsive primarily. to thetemperature of the ambient medium to be controlled and operativelyconnected to said switching means for actuating the same to circuitopening and circuit closing positions, the 'said actuator solelyoperating said switching means to both positions by reason of itsphysical distortion arising from its own temperature, movement of saidswitching means by said actu ator to one of its positions being effectedsolely by the temperature of the ambient medium whereby when saidswitching means is moved to said first position the transmission of,auxiliary' heatto said actuator is controlled whereby it then becomesresponsive to the combined action of the temperature of the ambientmedium to be controlled-and the auxiliary heat for moving said switchingmeans to its other position.

33. A control device for maintaining the'temperature of an ambientmedium substantially uniform comprising in combination electric switching means, and a thermal device influenced primarily by the ambienttemperature beingoperatively connected thereto for actuating the same,

said thermal device moving said switching means -to circuit closedposition solely as a result of a fall in the ambient temperature to becontrolled to restore said temperature to substantially normal value,the closing of said switching means, controlling an auxiliary supply pfheat to said device whereby it"actuates said switching means to openposition as a result ofthe combined action of a rise in the ambienttemperature to be controlled and the auxiliary heat.

34. A control device. for maintaining the temperature of the ambientmediumsubstantially uniform comprising in combination a thermal deviceprimarily influenced by the ambient temperature, andelectric switchingmeans actuated thereby, said thermal device solely by reason of its ownphysical distortion moving said switching means to closed position whenthe ambient temheated for influencing said thermal device whereby theswitching means is actuated to open posielectric circuit comprising aheat operated element including. a thermostatic metallic coil, a circuitclosing device including a tiltable vessel, terminals and a fluentconductor therein, means intermediate said circuit closing device andsaid heat operated element for operating the former to break the circuitby the heat expansion of the latter and means for varying the point atwhich the said intermediate means will cause circuit breaking movementof said device without changing the relative positions 01 said deviceand said tion beiorethe ambient temperature of the space element. to beheated rises to that point at which said LOUIS A. M. PHELAN. switchingmeans would otherwise be opened. CLIFFORD HO'IUHKISS.

36. A thermostatic device for controlling an DISCLAIM-ER- Re.19,235.Zouis A. M. Phelan, Chicago, Patent May 28, 1941, by theassignee, 17w

ELECTRICAL APPARATUS.

111., and 011370112 Hotchkiss,Elkha1-t, Inddated July 10, 1934.Disclaimer filed Brown Instrument Company.

' Hereby enters this disclaimer to claims 31, 32, 3s, and 35 in saidspecification.

[Qflic'ial 0am June 24, 1941.

heated for influencing said thermal device whereby the switching meansis actuated to open posielectric circuit comprising a heat operatedelement including. a thermostatic metallic coil, a circuit closingdevice including a tiltable vessel, terminals and a fluent conductortherein, means intermediate said circuit closing device and said heatoperated element for operating the former to break the circuit by theheat expansion of the latter and means for varying the point at whichthe said intermediate means will cause circuit breaking movement of saiddevice without changing the relative positions 01 said device and saidtion beiorethe ambient temperature of the space element. to be heatedrises to that point at which said LOUIS A. M. PHELAN. switching meanswould otherwise be opened. CLIFFORD HO'IUHKISS.

36. A thermostatic device for controlling an DISCLAIM-ER- Re.19,235.Zouis A. M. Phelan, Chicago, Patent May 28, 1941, by theassignee, 17w

ELECTRICAL APPARATUS.

111., and 011370112 Hotchkiss,Elkha1-t, Inddated July 10, 1934.Disclaimer filed Brown Instrument Company.

' Hereby enters this disclaimer to claims 31, 32, 3s, and 35 in saidspecification.

[Qflic'ial 0am June 24, 1941.

